Common surfaces problems
Surfaces against background
Problem: Surfaces have jagged edges against the background.
Composite Rendering may be ON.
Do one of the following:
See Composite Rendering in Render > Globals.
Set Composite RenderingOFF (under Render Globals).
See Anti-aliasing Levels in Render > Globals
.First increase Threshold under Render Globals. If the jagged edges persist, increase Minimum and Maximum Anti-aliasing Levels.
Surface silhouettes or edges appear faceted
Problem: Surface silhouettes or edges appear faceted.
See Mesh Tolerance (cm) in Render > Globals .
Decrease the Mesh Tolerance value (under Render Globals).
Cracks appear between surfaces
Problem: Cracks appear between surfaces that should be aligned.
Do one of the following:
Attach the surfaces together using Object Edit > Attach > Attach
.See Mesh Tolerance (cm) in Render > Globals
.Decrease the Mesh Tolerance value (under Render Globals).
Camera’s Auto Render Clip parameter
Problem: Choppy surface artifacts
See Auto Render Clip in Windows > Editors > Cameras 
.
If you are not rendering animation, or not using shadow maps, or not outputting depth files, turn on the camera’s Auto Render Clip parameter.
See ClippingNear/Far in Windows > Editors > Cameras .
Otherwise, increase the camera’s ClippingNear value.